Fuel delivery systems for direct injection applications, such as, for example, fuel-injected engines used in various types of on-road and off-road vehicles, typically include one or more fuel rails having a plurality of fuel injectors associated therewith. In such applications, the fuel rails may include a plurality of apertures or outlets in which injector sockets or cups are affixed. The fuel injectors are then inserted into the injector cups so as to allow for the fuel flowing in the fuel rail to be communicated to the fuel injectors. The fuel communicated from the fuel rail to the fuel injectors is then communicated to the combustion chamber of the engine associated with the fuel delivery system.
A challenge to these systems resides in the retention of the fuel injectors in the cups of the fuel rail in view of the relatively high system pressure (i.e., on the order of 10-30 MPa (1450-4350 psi)) and the pressure created as a result of combustion events occurring in the combustion chamber of the engine. One approach to meet this challenge has been to employ oversized standard external injector clips. In such an approach, the injector is inserted into the fuel rail and then an injector clip is coupled to both the injector and the cup to secure and retain the injector to and within the cup, while at the same time withstanding the load applied to the injector as a result of both the pressure of the system and the pressure created by the occurrence of a combustion event. Another approach has been the utilization of redundant clips to ensure the retention of the injector within the cup.
These approaches, however, are not without their disadvantages. For example, the respective size and positional tolerances of the cylinder head, fuel rail and injector causes the injector to not be exactly parallel with the injector cup. As a result, when the cup, injector and clip are assembled, there is a certain degree of misalignment between the injector and the cup. As a result, the load applied to the injector, clip, and/or rail primarily by the high pressure attendant in the system is overloaded to one side of the injector, thereby resulting in the application of a bending moment on the injector and/or clip, which can adversely impact the retention and orientation of the fuel injector within the cup of the fuel rail.
Therefore, there is a need for a fuel delivery system that will minimize and/or eliminate one or more of the above-identified deficiencies.